الأحد، 25 سبتمبر 2011

acute transfusion lung injury" ATLI"...

acute transfusion lung injury "ATLI"

Transfusion-related acute lung injury 

(TRALI) is a complication following 

transfusion of blood products and is 

potentially a life-threatening adverse event of 

transfusion.


 The first case of fatal pulmonary

 edema following transfusion was reported in

the 1950 


TRALI is a clinical syndrome 

characterized by the acute onset of 

respiratory distress in a patient who

received transfusion. It can present with

 a variety of symptoms and signs, most 

commonly worsening of respiratory 

function. Patients present with 

respiratory distress (dyspnea,

 tachypnea), hypoxia, hypotension (less

 commonly hypertension), fever, 

tachycardia and cyanosis, pulmonary 

edema (frothy pulmonary secretions),

 and bilateral fluffy infiltrates on chest 

radiograph. The majority of cases occur 

during or within 1 to 2 h of transfusion. 


. INTRODUCTION

Transfusion-related acute lung injury 

(TRALI) is one of the most common 

causes of transfusion associated major

morbidity and death.

 The results from 

many national haemovigillance

 programs have identified TRALI as a 

significant adverse event of transfusion,

 and the reported mortality rates vary 

from 5 to 25%.  TRALI is a life-

threatening adverse event of 

transfusion.


Investigators have shown that non-

cardiogenic lung edema is also an 

important pulmonary complication of 

transfusion. Since Barnard’s initial 

description in 1951, (6) non-cardiogenic 

lung edema related to transfusion has 

been widely reported using various 

names, including non-cardiogenic 

pulmonary edema, pulmonary 

hypersensitivity and severe allergic 

pulmonary edema. In 1983 Popovsky et 

al. (7,8) coined the term "transfusion-

related acute lung injury".


TRALI has been reported from all types

 of blood components including whole

blood, red cells, aphaeresis platelets, 

whole blood platelets, fresh frozen 

plasma, cryoprecipitate, granulocytes, 

stem cell products and even IV 

immunoglobulin preparations.


According to the literature, the 

incidence is 1:5000 for blood 

components  with subsequent 

reports ranging from 1:432 for whole 

blood platelets to 1:557,000 for red 

cells.  The most implicated are 

plasma-rich components, such as 

plasma and aphaeresis platelets. 

TRALI is under- diagnosed and under- 

reported as many clinicians are not 

familiar with the syndrome.

 This is 

equally true for severe cases of TRALI 

where transfusion may not be 

considered as a possible cause and may 

be regarded as acute respiratory 

distress syndrome (ARDS) but also for 

mild case where mechanical ventilation 

is not required.

 TRALI can be 

misdiagnosed as TACO (Transfusion 

Associated Circulatory Overload) as

 occurred in the French haemovigilance

 network. 

Patients who are at risk for developing 

TRALI are still not properly identified.




(a)    Acute onset of acute lung injury (ALI)



  • (b)    Hypoxemia (PaO2/FiO2 (ratio of

  •  partial pressure of arterial O2 to the fraction

  •  of inspired O2) ≤300 and must be adjusted

  •  downward with increasing altitude 

  • or SpO2≤90% on room air or other

  •  clinical evidence)

  • (c)    Bilateral lung infiltrates on frontal chest

  •  radiograph

  • (d)    No evidence of left atrial hypertension


  •  (i.e., transfusion-associated circulatory overload)

  • (e)  
  •   Occurrence during or within 6 h after

  •  completion of transfusion

  • (f)    No temporal relationship to 


  • an alternative risk factor for ALI

  • (g)    New ALI and no other ALI risk factors


  •  present including aspiration, multiple


  •  trauma, pneumonia, cardiopulmonary


  •  bypass, burn injury, toxic inhalation, lung


  •  contusion, acute pancreatitis, drug overdose


  • , near drowning, shock and sepsis

  • (h)    If one or more ALI risk factors are


  •  present, possible TRALI should be diagnosed


  •  (in patients with an alternative ALI risk


  •  factor, TRALI is still possible)

Classic TRALI is therefore a clinical

 syndrome. Sometimes, a single unit of blood

 or blood product is implicated in causing the

 syndrome. Patients with classic TRALI


 should not have other risk factors for ALI

 and, thus, the transfusion is the only

 identifiable cause of the respiratory failure.





Characteristics of the “classic TRALI 
syndrome” are: time of onset within 2
 hours (usually up to 6 hours); rapid 

development; no other risk factors for 
ALI except transfusion; anti-neutrophil
 antibodies pathophysiology and onset 
after asingle unit of blood product

Characteristics of the “delayed TRALI 
syndrome” are: time of onset 6-72 
hours after transfusion; slow 
development of 

clinical presentation; patients have 
other risk factors for ALI (i.e. sepsis,

 aspiration, near-drowning, 
disseminated 

intravascular coagulation, trauma, 
pneumonia, drug overdose, fracture, 
burns and cardiopulmonary bypass); 
two- step 
pathophysiology and common after 

massive transfusion (40-57%). 

pathophysiology

The exact mechanism of TRALI is still not 

fully understood. 

 At present we know that the common

 denominator is the end of the pathway which

 presents with increased pulmonary capillary 

permeability, and results in movement of 

plasma into the alveolar space causing 

pulmonary edema. Two possible theorie

s have been proposed to explain the 

pathogenesis of TRALI. 


The first suggests an antibody mediated 

reaction after transfusion. The antibody-

mediated model postulates that the react

ion is secondary to passive transfusion of 

specific donor antibodies against recipient 

antigens (human leukocyte antigen (HLA) 

specific, mostly HLA-A2 or anti-granulocyte 

specific antibodies like human neutrophil 

antigen (HNA)-1a, -1b, -3a or HLA 1) or 

infusion of donor antigens (leucocytes) in 

recipient who already has antibodies again

st them. 



This antibody-antigen interaction can cause 

complement activation, resulting in the 

pulmonary sequestration and activation of 

neutrophils, endothelial cell damage, and a 

capillary leak syndrome in the lungs 

manifesting as TRALI.


 There is evidence that TRALI is more 

common in recipients of blood products from 

multiparous female donors who are more 


likely to possess anti-HLA antibodies and 


anti–neutrophil-specific antibodies. 


 However, in about 5-15% of cases, no 

antibody is identified in either the donor or 

recipient. The second is a two-event model.

 The first event (first hit) is the clinical 

condition of the patient resulting in 

pulmonary endothelial activation an

d polimorphonuclear (PMN) sequestration,

 and the second event is the transfusion of a 

biologic response modifier (including anti-

granulocyte antibodies, lipids, and CD40 

ligand) that activates these adherent PMNs 

resulting in endothelial damage, capillary leak,

 and TRALI. These two mechanisms of injury 

may not be mutually exclusive and a patient 

may develop TRALI through either one or 

both mechanisms

prevention


All TRALI reactions should be reported to the 

transfusion service. All associated donors are 

tested for HLA class I and II antibodies as well

 as HNA antibodies. As the transfused units 

are usually not available for testing, 


this 

involves recalling the donors. Associated

 donors may continue donating while being 

investigated but only plasma for fractionation 

is used. All implicated donors (i.e. donors who

 
are cross match positive with the patient’s 

leucocytes or donors who have the cognate 

antibody to HLA class I, II or neutrophil 

antigens of the patient) are permanently 

deferred from donation.




ليست هناك تعليقات:

إرسال تعليق